The present invention relates to a mechanically-operated magazine-unloading, sheet-feeding mechanism for a sheet processing machine.
The prior art includes prior U.S. patents of A. Rutishauser, U.S. Pat. No. 4,240,622, issued Dec. 23, 1980; T. Rutishauser et al, U.S. Pat. No. 4,268,021, issued May 19, 1981; and a related mechanism is shown in the copending U.S. patent application of T. Rutishauser, Ser. No. 234,105, filed Feb. 12, 1981, now U.S. Pat. No. 4,364,551.
There are many instances where a machine that processes sheets of material one by one as the sheets are individually withdrawn from a stack of sheets and fed in a series along a path which goes through a processing station at which something is done to each sheet during its time in the station.
The mechanism of the present invention was developed for a machine for printing on or otherwise providing records on sheets of flexible material such as paper, card-stock or the like. The problem to be solved is how to serially abstract the sheets from a stack in the magazine and forward them one-by-one to and through the station where they are each printed on, recorded on or otherwise processed.
German OS 28 54 695 shows one such mechanism for use on that kind of machine. The prior art mechanism uses an electrically-operated switch that is controlled by a photo-electric cell having a beam which intersects the sheet path at the outlet of the magazine. An electromagnetic clutch is provided for the sheet conveyor, this clutch being electrically controlled by the switch. The disadvantage inherent in this prior art mechanism is that it requires auxiliary electric power to be fed to sites on the machine where everything else is mechanically powered.